Delayed-type, T-lymphocyte–mediated contact allergy to a chemical substance
Typical hand contact allergens include nickel (e.g., cell phones, tools, or jewelry), potassium dichromate/chromates (e.g., in leather or cement), rubber additives (including thiuram mix, carba mix, paraphenylenediamine [PPD], and mercaptobenzothiazole, often in gloves), cobalt chloride, and preservatives (e.g., in creams or cosmetics)
Cigarettes - may contain contact allergens in filters, paper, tobacco, menthol (mint, peppermint), licorice, colophony, formaldehyde
Hand jewelry ACD vs. "Wedding ring rash" occlusion dermatitis due to irritation from the buildup of soap, moisture, and debris underneath the ring
Diagnosis is supported by a history of exposure plus positive reaction to patch testing with contact allergens
Protein contact dermatitis
Frequently occurs in patients in professions involving food
Subtype of allergic contact dermatitis.
Initially, the reaction to proteins is contact urticaria, but eczema may develop. IgE reactions to specific proteins are often detected with SPT or sIgE
Latex allergy is a related phenomenon
Hybrid hand eczema
Combination of above
Differentiating ACD vs. ICD vs. AD: Location on hand can provide clues:
Dorsal hand and finger combined with the volar wrist suggest AD
ICD commonly presents as a localized dermatitis without vesicles in the webs of fingers; it extends onto the dorsal and ventral surfaces (‘‘apron’’ pattern), dorsum of the hands, palms, and ball of the thumb
ACD often has vesicles and favors the fingertips, nail folds, and dorsum of the hands and less commonly involves the palms
Morphologic Classification
Comment
Recurrent vesicular hand eczema (aka pomphpolyx, dyshidrotic eczema)
Recurrent vesicular eruptions on the palms and the palmar and lateral sides of the fingers (often also have eruptions on the soles of the feet)
A contact allergic reaction or atopic hand eczema may also be manifested as an identical vesicular eruption
Hyperkeratotic hand eczema
More common in middle-aged and elderly persons and in men
Sharply demarcated areas of thick scaling or hyperkeratosis on the palms (and frequently on the soles) often with painful fissures (vesicles are absent)
Differential
May be confused with psoriasis, but there is little or none of the redness and none of the scaling or nail changes typical of psoriasis
Lichen planus - may mimic hyperkeratotic hand eczema
Chronic fingertip dermatitis or pulpitis
Dry, fissured, scaling dermatitis of the fingertips, with occasional episodes of vesicles
On occasion, the cause may be a contact allergy
Nummular hand eczema
Round, coin-sized eczematous patches that appear on the back of the hands
May be a manifestation of ICD, ACD, or AD
Conditions with appearance similar to hand eczema
Comment
Psoriasis
Lesions are dry, scaling, and sharply demarcated, and there is an absence of vesicles
Lesions elsewhere on the body are characteristic
Palmoplantar pustulosis, a variant of psoriasis, should be considered when sterile pustules are present
Fungal infection (mycosis)
A fungal infection is especially likely when one hand is more prominently involved
Dry scaling of the palmar creases is characteristic
Scabies
Papules and burrows are present, likely to appear in the web spaces of the hands and the volar aspect of the wrists
Itchy papules are often present on the trunk and limbs
Granuloma annulare
Round or oval patches, with a demarcated raised edge, are characteristic and appear primarily on the dorsal side of the hands
Herpes simplex
Localized recurrent attacks of clustered vesicles, which are very painful but not itchy
Differential Diagnosis
Management
References